Re: [PATCH v15 10/15] FWU: Add support for the FWU Multi Bank Update feature

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

Hi Sughosh, 

Ideally this would be better of as a different FMP, but I understand we are
missing some information (the capsule header) on the FMP level.

I think we can include it as is for now and have another look when we add
support for more boards

On Fri, Oct 21, 2022 at 06:16:03PM +0530, Sughosh Ganu wrote:
> The FWU Multi Bank Update feature supports updating firmware images
> to one of multiple sets(also called banks) of images. The firmware
> images are clubbed together in banks, with the system booting images
> from the active bank. Information on the images such as which bank
> they belong to is stored as part of the metadata structure, which is
> stored on the same storage media as the firmware images on a dedicated
> partition.
> 
> At the time of update, the metadata is read to identify the bank to
> which the images need to be flashed(update bank). On a successful
> update, the metadata is modified to set the updated bank as active
> bank to subsequently boot from.
> 
> Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
> ---
> Changes since V14:
> * Initialise the return value to EFI_INVALID_PARAMETER in
>   fwu_empty_capsule_process() and get rid of the else part as
>   suggested by Ilias
> * Remove the superfluous assignment of EFI_SUCCESS in
>   fwu_post_update_process() as suggested by Ilias
> * Add a check for fwu_empty_capsule_checks_pass() to allow application
>   of empty capsules only in trial state
> 
>  drivers/Kconfig               |   2 +
>  drivers/Makefile              |   1 +
>  include/fwu.h                 |  30 +++++
>  lib/Kconfig                   |   6 +
>  lib/Makefile                  |   1 +
>  lib/efi_loader/efi_capsule.c  | 210 +++++++++++++++++++++++++++++++++-
>  lib/efi_loader/efi_firmware.c |  14 +++
>  lib/fwu_updates/Kconfig       |  33 ++++++
>  lib/fwu_updates/Makefile      |   7 ++
>  lib/fwu_updates/fwu.c         |  22 ++++
>  10 files changed, 324 insertions(+), 2 deletions(-)
>  create mode 100644 lib/fwu_updates/Kconfig
>  create mode 100644 lib/fwu_updates/Makefile
> 
> diff --git a/drivers/Kconfig b/drivers/Kconfig
> index 8b6fead351..75ac149d31 100644
> --- a/drivers/Kconfig
> +++ b/drivers/Kconfig
> @@ -44,6 +44,8 @@ source "drivers/fuzz/Kconfig"
>  
>  source "drivers/fpga/Kconfig"
>  
> +source "drivers/fwu-mdata/Kconfig"
> +
>  source "drivers/gpio/Kconfig"
>  
>  source "drivers/hwspinlock/Kconfig"
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 9d9f69a3c9..253cbfb71d 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -85,6 +85,7 @@ obj-y += cache/
>  obj-$(CONFIG_CPU) += cpu/
>  obj-y += crypto/
>  obj-$(CONFIG_FASTBOOT) += fastboot/
> +obj-$(CONFIG_FWU_MDATA) += fwu-mdata/
>  obj-y += misc/
>  obj-$(CONFIG_MMC) += mmc/
>  obj-$(CONFIG_NVME) += nvme/
> diff --git a/include/fwu.h b/include/fwu.h
> index a8ed67b0e0..0919ced812 100644
> --- a/include/fwu.h
> +++ b/include/fwu.h
> @@ -98,6 +98,7 @@ struct fwu_mdata_ops {
>  };
>  
>  #define FWU_MDATA_VERSION	0x1
> +#define FWU_IMAGE_ACCEPTED	0x1
>  
>  /*
>  * GUID value defined in the FWU specification for identification
> @@ -107,6 +108,24 @@ struct fwu_mdata_ops {
>  	EFI_GUID(0x8a7a84a0, 0x8387, 0x40f6, 0xab, 0x41, \
>  		 0xa8, 0xb9, 0xa5, 0xa6, 0x0d, 0x23)
>  
> +/*
> +* GUID value defined in the Dependable Boot specification for
> +* identification of the revert capsule, used for reverting
> +* any image in the updated bank.
> +*/
> +#define FWU_OS_REQUEST_FW_REVERT_GUID \
> +	EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \
> +		 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0)
> +
> +/*
> +* GUID value defined in the Dependable Boot specification for
> +* identification of the accept capsule, used for accepting
> +* an image in the updated bank.
> +*/
> +#define FWU_OS_REQUEST_FW_ACCEPT_GUID \
> +	EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
> +		 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
> +
>  /**
>   * fwu_check_mdata_validity() - Check for validity of the FWU metadata copies
>   *
> @@ -379,4 +398,15 @@ u8 fwu_update_checks_pass(void);
>   */
>  u8 fwu_empty_capsule_checks_pass(void);
>  
> +/**
> + * fwu_trial_state_ctr_start() - Start the Trial State counter
> + *
> + * Start the counter to identify the platform booting in the
> + * Trial State. The counter is implemented as an EFI variable.
> + *
> + * Return: 0 if OK, -ve on error
> + *
> + */
> +int fwu_trial_state_ctr_start(void);
> +
>  #endif /* _FWU_H_ */
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 6121c80dc8..6abe1d0a86 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -978,3 +978,9 @@ config LMB_RESERVED_REGIONS
>  	  memory blocks.
>  
>  endmenu
> +
> +menu "FWU Multi Bank Updates"
> +
> +source lib/fwu_updates/Kconfig
> +
> +endmenu
> diff --git a/lib/Makefile b/lib/Makefile
> index e3deb15287..f2cfd1e428 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_EFI) += efi/
>  obj-$(CONFIG_EFI_LOADER) += efi_driver/
>  obj-$(CONFIG_EFI_LOADER) += efi_loader/
>  obj-$(CONFIG_CMD_BOOTEFI_SELFTEST) += efi_selftest/
> +obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu_updates/
>  obj-$(CONFIG_LZMA) += lzma/
>  obj-$(CONFIG_BZIP2) += bzip2/
>  obj-$(CONFIG_FIT) += libfdt/
> diff --git a/lib/efi_loader/efi_capsule.c b/lib/efi_loader/efi_capsule.c
> index 397e393a18..1163a2ee30 100644
> --- a/lib/efi_loader/efi_capsule.c
> +++ b/lib/efi_loader/efi_capsule.c
> @@ -14,6 +14,7 @@
>  #include <env.h>
>  #include <fdtdec.h>
>  #include <fs.h>
> +#include <fwu.h>
>  #include <hang.h>
>  #include <malloc.h>
>  #include <mapmem.h>
> @@ -32,6 +33,12 @@ static const efi_guid_t efi_guid_firmware_management_capsule_id =
>  		EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
>  const efi_guid_t efi_guid_firmware_management_protocol =
>  		EFI_FIRMWARE_MANAGEMENT_PROTOCOL_GUID;
> +const efi_guid_t fwu_guid_os_request_fw_revert =
> +		FWU_OS_REQUEST_FW_REVERT_GUID;
> +const efi_guid_t fwu_guid_os_request_fw_accept =
> +		FWU_OS_REQUEST_FW_ACCEPT_GUID;
> +
> +#define FW_ACCEPT_OS	(u32)0x8000
>  
>  #ifdef CONFIG_EFI_CAPSULE_ON_DISK
>  /* for file system access */
> @@ -386,6 +393,132 @@ efi_status_t efi_capsule_authenticate(const void *capsule, efi_uintn_t capsule_s
>  }
>  #endif /* CONFIG_EFI_CAPSULE_AUTHENTICATE */
>  
> +static __maybe_unused bool fwu_empty_capsule(struct efi_capsule_header *capsule)
> +{
> +	return !guidcmp(&capsule->capsule_guid,
> +			&fwu_guid_os_request_fw_revert) ||
> +		!guidcmp(&capsule->capsule_guid,
> +			 &fwu_guid_os_request_fw_accept);
> +}
> +
> +static __maybe_unused efi_status_t fwu_to_efi_error(int err)
> +{
> +	efi_status_t ret;
> +
> +	switch(err) {
> +	case 0:
> +		ret = EFI_SUCCESS;
> +		break;
> +	case -ERANGE:
> +	case -EIO:
> +		ret = EFI_DEVICE_ERROR;
> +		break;
> +	case -EINVAL:
> +		ret = EFI_INVALID_PARAMETER;
> +		break;
> +	case -ENODEV:
> +		ret = EFI_NOT_FOUND;
> +		break;
> +	default:
> +		ret = EFI_OUT_OF_RESOURCES;
> +	}
> +
> +	return ret;
> +}
> +
> +static __maybe_unused efi_status_t fwu_empty_capsule_process(
> +	struct efi_capsule_header *capsule)
> +{
> +	int status;
> +	u32 active_idx;
> +	efi_guid_t *image_guid;
> +	efi_status_t ret = EFI_INVALID_PARAMETER;
> +
> +	if (!guidcmp(&capsule->capsule_guid,
> +		     &fwu_guid_os_request_fw_revert)) {
> +		/*
> +		 * One of the previously updated image has
> +		 * failed the OS acceptance test. OS has
> +		 * requested to revert back to the earlier
> +		 * boot index
> +		 */
> +		status = fwu_revert_boot_index();
> +		ret = fwu_to_efi_error(status);
> +		if (ret == EFI_SUCCESS)
> +			log_debug("Reverted the FWU active_index. Recommend rebooting the system\n");
> +		else
> +			log_err("Failed to revert the FWU boot index\n");
> +	} else if (!guidcmp(&capsule->capsule_guid,
> +			    &fwu_guid_os_request_fw_accept)) {
> +		/*
> +		 * Image accepted by the OS. Set the acceptance
> +		 * status for the image.
> +		 */
> +		image_guid = (void *)(char *)capsule +
> +			capsule->header_size;
> +
> +		status = fwu_get_active_index(&active_idx);
> +		ret = fwu_to_efi_error(status);
> +		if (ret != EFI_SUCCESS) {
> +			log_err("Unable to get the active_index from the FWU metadata\n");
> +			return ret;
> +		}
> +
> +		status = fwu_accept_image(image_guid, active_idx);
> +		ret = fwu_to_efi_error(status);
> +		if (ret != EFI_SUCCESS)
> +			log_err("Unable to set the Accept bit for the image %pUs\n",
> +				image_guid);
> +	}
> +
> +	return ret;
> +}
> +
> +static __maybe_unused void fwu_post_update_checks(
> +	struct efi_capsule_header *capsule,
> +	bool *fw_accept_os, bool *capsule_update)
> +{
> +	if (fwu_empty_capsule(capsule))
> +		*capsule_update = false;
> +	else
> +		if (!*fw_accept_os)
> +			*fw_accept_os =
> +				capsule->flags & FW_ACCEPT_OS ? true : false;
> +}
> +
> +static __maybe_unused efi_status_t fwu_post_update_process(bool fw_accept_os)
> +{
> +	int status;
> +	uint update_index;
> +	efi_status_t ret;
> +
> +	status = fwu_plat_get_update_index(&update_index);
> +	if (status < 0) {
> +		log_err("Failed to get the FWU update_index value\n");
> +		return EFI_DEVICE_ERROR;
> +	}
> +
> +	/*
> +	 * All the capsules have been updated successfully,
> +	 * update the FWU metadata.
> +	 */
> +	log_debug("Update Complete. Now updating active_index to %u\n",
> +		  update_index);
> +	status = fwu_set_active_index(update_index);
> +	ret = fwu_to_efi_error(status);
> +	if (ret != EFI_SUCCESS) {
> +		log_err("Failed to update FWU metadata index values\n");
> +	} else {
> +		log_debug("Successfully updated the active_index\n");
> +		if (fw_accept_os) {
> +			status = fwu_trial_state_ctr_start();
> +			if (status < 0)
> +				ret = EFI_DEVICE_ERROR;
> +		}
> +	}
> +
> +	return ret;
> +}
>  
>  /**
>   * efi_capsule_update_firmware - update firmware from capsule
> @@ -408,7 +541,32 @@ static efi_status_t efi_capsule_update_firmware(
>  	int item;
>  	struct efi_firmware_management_protocol *fmp;
>  	u16 *abort_reason;
> +	efi_guid_t *image_type_id;
>  	efi_status_t ret = EFI_SUCCESS;
> +	int status;
> +	uint update_index;
> +	bool fw_accept_os;
> +
> +	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +		if (fwu_empty_capsule_checks_pass() &&
> +		    fwu_empty_capsule(capsule_data))
> +			return fwu_empty_capsule_process(capsule_data);
> +
> +		if (!fwu_update_checks_pass()) {
> +			log_err("FWU checks failed. Cannot start update\n");
> +			return EFI_INVALID_PARAMETER;
> +		}
> +
> +
> +		/* Obtain the update_index from the platform */
> +		status = fwu_plat_get_update_index(&update_index);
> +		if (status < 0) {
> +			log_err("Failed to get the FWU update_index value\n");
> +			return EFI_DEVICE_ERROR;
> +		}
> +
> +		fw_accept_os = capsule_data->flags & FW_ACCEPT_OS ? 0x1 : 0x0;
> +	}
>  
>  	/* sanity check */
>  	if (capsule_data->header_size < sizeof(*capsule) ||
> @@ -495,6 +653,34 @@ static efi_status_t efi_capsule_update_firmware(
>  			efi_free_pool(abort_reason);
>  			goto out;
>  		}
> +
> +		if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +			image_type_id = &image->update_image_type_id;
> +			if (!fw_accept_os) {
> +				/*
> +				 * The OS will not be accepting the firmware
> +				 * images. Set the accept bit of all the
> +				 * images contained in this capsule.
> +				 */
> +				status = fwu_accept_image(image_type_id,
> +							  update_index);
> +			} else {
> +				status = fwu_clear_accept_image(image_type_id,
> +								update_index);
> +			}
> +			ret = fwu_to_efi_error(status);
> +			if (ret != EFI_SUCCESS) {
> +				log_err("Unable to %s the accept bit for the image %pUs\n",
> +					fw_accept_os ? "clear" : "set",
> +					image_type_id);
> +				goto out;
> +			}
> +
> +			log_debug("%s the accepted bit for Image %pUs\n",
> +				  fw_accept_os ? "Cleared" : "Set",
> +				  image_type_id);
> +		}
> +
>  	}
>  
>  out:
> @@ -1103,6 +1289,9 @@ efi_status_t efi_launch_capsules(void)
>  	u16 **files;
>  	unsigned int nfiles, index, i;
>  	efi_status_t ret;
> +	bool capsule_update = true;
> +	bool update_status = true;
> +	bool fw_accept_os = false;
>  
>  	if (check_run_capsules() != EFI_SUCCESS)
>  		return EFI_SUCCESS;
> @@ -1130,12 +1319,19 @@ efi_status_t efi_launch_capsules(void)
>  		ret = efi_capsule_read_file(files[i], &capsule);
>  		if (ret == EFI_SUCCESS) {
>  			ret = efi_capsule_update_firmware(capsule);
> -			if (ret != EFI_SUCCESS)
> +			if (ret != EFI_SUCCESS) {
>  				log_err("Applying capsule %ls failed.\n",
>  					files[i]);
> -			else
> +				update_status = false;
> +			} else {
>  				log_info("Applying capsule %ls succeeded.\n",
>  					 files[i]);
> +				if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +					fwu_post_update_checks(capsule,
> +							       &fw_accept_os,
> +							       &capsule_update);
> +				}
> +			}
>  
>  			/* create CapsuleXXXX */
>  			set_capsule_result(index, capsule, ret);
> @@ -1143,6 +1339,7 @@ efi_status_t efi_launch_capsules(void)
>  			free(capsule);
>  		} else {
>  			log_err("Reading capsule %ls failed\n", files[i]);
> +			update_status = false;
>  		}
>  		/* delete a capsule either in case of success or failure */
>  		ret = efi_capsule_delete_file(files[i]);
> @@ -1150,8 +1347,17 @@ efi_status_t efi_launch_capsules(void)
>  			log_err("Deleting capsule %ls failed\n",
>  				files[i]);
>  	}
> +
>  	efi_capsule_scan_done();
>  
> +	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +		if (capsule_update == true && update_status == true) {
> +			ret = fwu_post_update_process(fw_accept_os);
> +		} else if (capsule_update == true && update_status == false) {
> +			log_err("All capsules were not updated. Not updating FWU metadata\n");
> +		}
> +	}
> +
>  	for (i = 0; i < nfiles; i++)
>  		free(files[i]);
>  	free(files);
> diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
> index 30cafd15ca..93e2b01c07 100644
> --- a/lib/efi_loader/efi_firmware.c
> +++ b/lib/efi_loader/efi_firmware.c
> @@ -10,6 +10,7 @@
>  #include <charset.h>
>  #include <dfu.h>
>  #include <efi_loader.h>
> +#include <fwu.h>
>  #include <image.h>
>  #include <signatures.h>
>  
> @@ -389,6 +390,7 @@ efi_status_t EFIAPI efi_firmware_raw_set_image(
>  	efi_status_t (*progress)(efi_uintn_t completion),
>  	u16 **abort_reason)
>  {
> +	int ret;
>  	efi_status_t status;
>  
>  	EFI_ENTRY("%p %d %p %zu %p %p %p\n", this, image_index, image,
> @@ -401,6 +403,18 @@ efi_status_t EFIAPI efi_firmware_raw_set_image(
>  	if (status != EFI_SUCCESS)
>  		return EFI_EXIT(status);
>  
> +	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
> +		/*
> +		 * Based on the value of update bank, derive the
> +		 * image index value.
> +		 */
> +		ret = fwu_get_image_index(&image_index);
> +		if (ret) {
> +			log_debug("Unable to get FWU image_index\n");
> +			return EFI_EXIT(EFI_DEVICE_ERROR);
> +		}
> +	}
> +
>  	if (dfu_write_by_alt(image_index - 1, (void *)image, image_size,
>  			     NULL, NULL))
>  		return EFI_EXIT(EFI_DEVICE_ERROR);
> diff --git a/lib/fwu_updates/Kconfig b/lib/fwu_updates/Kconfig
> new file mode 100644
> index 0000000000..78759e6618
> --- /dev/null
> +++ b/lib/fwu_updates/Kconfig
> @@ -0,0 +1,33 @@
> +config FWU_MULTI_BANK_UPDATE
> +	bool "Enable FWU Multi Bank Update Feature"
> +	depends on EFI_CAPSULE_ON_DISK
> +	select PARTITION_TYPE_GUID
> +	select EFI_SETUP_EARLY
> +	imply EFI_CAPSULE_ON_DISK_EARLY
> +	select EVENT
> +	help
> +	  Feature for updating firmware images on platforms having
> +	  multiple banks(copies) of the firmware images. One of the
> +	  bank is selected for updating all the firmware components
> +
> +config FWU_NUM_BANKS
> +	int "Number of Banks defined by the platform"
> +	depends on FWU_MULTI_BANK_UPDATE
> +	help
> +	  Define the number of banks of firmware images on a platform
> +
> +config FWU_NUM_IMAGES_PER_BANK
> +	int "Number of firmware images per bank"
> +	depends on FWU_MULTI_BANK_UPDATE
> +	help
> +	  Define the number of firmware images per bank. This value
> +	  should be the same for all the banks.
> +
> +config FWU_TRIAL_STATE_CNT
> +	int "Number of times system boots in Trial State"
> +	depends on FWU_MULTI_BANK_UPDATE
> +	default 3
> +	help
> +	  With FWU Multi Bank Update feature enabled, number of times
> +	  the platform is allowed to boot in Trial State after an
> +	  update.
> diff --git a/lib/fwu_updates/Makefile b/lib/fwu_updates/Makefile
> new file mode 100644
> index 0000000000..1993088e5b
> --- /dev/null
> +++ b/lib/fwu_updates/Makefile
> @@ -0,0 +1,7 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (c) 2022, Linaro Limited
> +#
> +
> +obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu.o
> +obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_gpt.o
> diff --git a/lib/fwu_updates/fwu.c b/lib/fwu_updates/fwu.c
> index c9a9022a59..6e159c050c 100644
> --- a/lib/fwu_updates/fwu.c
> +++ b/lib/fwu_updates/fwu.c
> @@ -630,6 +630,28 @@ u8 fwu_empty_capsule_checks_pass(void)
>  	return in_trial && boottime_check;
>  }
>  
> +/**
> + * fwu_trial_state_ctr_start() - Start the Trial State counter
> + *
> + * Start the counter to identify the platform booting in the
> + * Trial State. The counter is implemented as an EFI variable.
> + *
> + * Return: 0 if OK, -ve on error
> + *
> + */
> +int fwu_trial_state_ctr_start(void)
> +{
> +	int ret;
> +	u16 trial_state_ctr;
> +
> +	trial_state_ctr = 0;
> +	ret = trial_counter_update(&trial_state_ctr);
> +	if (ret)
> +		log_err("Unable to initialise TrialStateCtr\n");
> +
> +	return ret;
> +}
> +
>  static int fwu_boottime_checks(void *ctx, struct event *event)
>  {
>  	int ret;
> -- 
> 2.34.1
> 

Heinrich pls shout if you think otherwise

Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>